Product Details

A special steel enterprise specializing in the production, research and development and sales of high alloy steel forgings

Spur Gear

Key words:

Classification:

Cylindrical Gear Forging

Hotline:

86 15239700030

86 13203901015

Consulting

1. Product Overview

Spur Gear is a fundamental and widely used mechanical transmission component with straight teeth parallel to the gear axis. It transmits motion and power through tooth meshing, featuring simple structure, easy manufacturing, and high transmission efficiency—critical for speed regulation and torque transfer in various equipment.

2. Core Structure & Features

Structure

Tooth direction: Parallel to the axis; tooth profile mostly involute (standard module) or cycloid for smooth meshing.
Key parts: Addendum (tooth top), dedendum (tooth root), tooth flank (meshing surface), pitch circle (reference for dimension calculation).
Installation: Via keyway connection, set screws, or bushing fit; adaptable to horizontal/vertical mounting.

Advantages

High efficiency (98%-99% for standard precision) with line contact and low friction loss.
Mature manufacturing process (forging, cutting, grinding) at lower cost than bevel/helical gears.
Easy maintenance: No axial force (only radial force during meshing); simple installation.
Versatile: Enables same/reverse direction transmission between parallel shafts; supports multi-stage combinations.

Limitations

Less stable at ultra-high speeds (impact/noise due to instant tooth engagement/disengagement).
Axial positioning required (via bearings) to prevent displacement.

3. Key Technical Parameters (Metric Standard)

Parameter	English Symbol	Definition	Common Range
Module	m	Tooth pitch/π (core design parameter)	0.5-50 mm (per GB/T 1357)
Number of Teeth	z	Total teeth (affects ratio/size)	12-200 (minimum 12 to avoid undercutting)
Pressure Angle	α	Force direction vs. tooth normal angle	20° (standard), 14.5° (old standard)
Transmission Ratio	i	Speed ratio (i=z₂/z₁=n₁/n₂)	1:1-1:10 (single-stage)
Face Width	b	Axial tooth length (affects load capacity)	5-300 mm (typically b=(5-15)m)
Precision Grade	-	Machining accuracy (tooth profile/pitch/orientation)	GB/T 10095 Grade 6-9 (Grade 6=high precision)
Rated Load	-	Maximum sustainable torque	10-5000 N·m (depends on module, material, precision)

4. Material & Manufacturing

Common Materials

Carbon/Alloy Steel: 45# (medium speed/load), 40Cr (quenched-tempered, heavy load), 20CrMnTi (carburized, high precision/load).
Stainless Steel: 304/316L (corrosion-resistant environments: chemical/food machinery).
Non-metallic: Nylon/POM (low load/noise: home appliances, micro-equipment).
Non-ferrous: Aluminum alloy (lightweight: aerospace), copper alloy (wear-resistant: low-speed transmission).

Key Processes

Blank Preparation: Forging (heavy-load), casting (large gears), bar cutting (small gears).
Tooth Machining: Hobbing (mass production), shaping (special/internal gears), grinding (Grade 6+ precision).
Heat Treatment: Quenching-tempering (strength/toughness), carburizing (tooth hardening).
Finishing: Gear grinding/honing (reduce roughness, improve meshing accuracy).
Surface Treatment: Galvanizing/chroming (rust-proof), black oxide (aesthetic/rust-proof).

5. Applications

Widely used in mechanical transmission systems:

General Machinery: Reducers, gearboxes, machine tools, conveyors, cranes.
Transportation: Automobiles (gearboxes/differentials), motorcycles, e-bikes.
Home Appliances: Washing machines, AC compressors, printers, treadmills.
Industrial Equipment: Motors, pumps, fans, textile/printing machinery.
Micro-equipment: Robot joints, medical devices, electronic transmission mechanisms.

6. Selection Notes

Module/teeth: Larger module for higher load; ratio determined by teeth ratio (match input/output speed).
Precision: Grade 6-7 (high speed/low noise: motors, precision machines); Grade 8-9 (general machinery: conveyors).
Material-heat treatment matching: Alloy steel + quenching (heavy/high-speed load); stainless steel (corrosive environments).
Backlash: Reserve 0.1-0.5 mm (compensate for center distance error/temperature change).
Lubrication: Use gear oil (e.g., GL-4) for high speed/load to reduce wear.